Grazing Planted Prairie in WI: Pollinator and Pasture Value

Progress report for FNC23-1376

Project Type: Farmer/Rancher
Funds awarded in 2023: $8,730.00
Projected End Date: 01/31/2025
Grant Recipient: Gwenyn Hill Farm
Region: North Central
State: Wisconsin
Project Coordinator:
Ryan Heinen
Gwenyn Hill Farm
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Project Information

Description of operation:

I (Ryan Heinen) have an education in natural resources with a Bachelor of Science degree in Ecology and Wildlife Management with 10 years work experience in conservation and natural resources and 10 years experience in livestock and organic farming. I am a graduate of the National Dairy Grazing Apprenticeship Program and South Dakota Grazing School. Currently I manage an 80 cow organic dairy herd, grass-fed beef herd and grass-fed lamb flock. Our farm also raises organic heritage grains and eggs. The whole 430 acre farm is certified organic. In addition to the field crops and livestock the farm includes a 10 acre vegetable CSA farm. The farm is being managed for soil health, and a number of oak woodlands and fields are being restored to native prairie and oak savanna to promote native species of all kinds.

Summary:

Farmland covers roughly ⅓ of the entire state of WI, with permanent pasture making up about 7% of the total farmland acreage. We know agriculture is a strong driver of biodiversity loss on the landscape that contributes to the disappearance of our native invertebrate pollinators. However, agriculture can also be a dedicated solution to this crisis by providing quality, long term habitat for wildlife. The goal of this project is to assess the effectiveness of planted prairie in supporting both pollinator life and productive cattle forage. We expect that the results from this project will inform if pastures can play a leading role in pollinator conservation and an on-the-ground study for graziers to refer to as they consider where or how prairie fits into their farm and grazing system.

Project Objectives:

To assess the compatibility of diverse planted prairie as both pollinator habitat and cattle pasture, we will survey the nutritional quality, floral resources, and invertebrate pollinator presence in a planted prairie pasture under different grazing pressures. In addition, we will also track how cattle grazing may influence (short-term) the prairie pasture plant community and collect baseline data on soil health in the prairie pasture system.

A diverse prairie mix was planted in the spring of 2018 and managed through two seasons of establishment before being burned and rotationally grazed for the first time in 2021. The prairie pasture will be divided into multiple paddocks of 1 - 3 acres to allow for a comparison of different grazing intensities with paddocks grazed at 0, 1, and 2 grazings through the growing season. Cattle will be rotated through each paddock, grazing for one to two days to a vegetation height of about 8” and then allowed to rest a minimum of 40 days before any subsequent grazing (if any). Pre- and post-grazed vegetation height will be measured using a pasture stick to track growth and recovery. Soils will also be collected and analyzed to assess soil characteristics, including bioactivity, to better inform how prairie pastures may compare to other pasture or cropping systems.

From late-May to September 1st of 2023 and 2024, we will collect bi-weekly (every other week) vegetation samples for lab analysis of forage quality to track how nutrients change throughout the growing season. Previous to and post grazing, each prairie paddock will be rapidly surveyed for vegetation composition (richness and abundance). In addition, prairie paddocks will be surveyed at least three times through the 2023 and 2024 growing season for floral resources (richness and abundance of blooms) and pollinator presence (richness and abundance). Floral and pollinator surveys will be conducted before and after grazing “disturbances” to assess how floral bloom and pollinator presence may change with time since grazing. To the best of our non-lethal means, pollinators will be identified to genus level (for butterflies) and functional grouping (for native bees) using Xerces’ Upper Midwest Community Science Pollinator Monitoring Guide.

During the two growing seasons of 2023 and 2024, we will:

  1. Evaluate forage quality of diverse planted prairie using laboratory diagnosis
  2. Evaluate flower richness and abundance through the growing season (June 1 - Oct. 1) of grazed prairie paddocks
  3. Survey plant recovery from grazing and changes in plant species composition; specifically looking at changes in cover of functional groupings of species: warm season grasses, cool season grasses, forbs.
  4. Survey pollinator presence (bees and butterflies)
  5. Record baseline information on soil health of prairie pasture
  6. Share findings through a field day, conference presentation, and a published “fact-sheet”

Cooperators

Click linked name(s) to expand/collapse or show everyone's info
  • Micah Kloppenburg (Educator and Researcher)
  • Rae Olson (Researcher)

Research

Materials and methods:

Prairie Forage Quality Research:  Each week from June 5 to July 17 forage tests were taken from a representative part of the prairie.  Forage samples were taken on noon one day each week.  Samples only included native prairie grass species. Forbs, legumes and non-native grass species were not included in the samples.  Forages samples were taken to Rock River Lab in Watertown WI as soon as sample was taken.  Two types of tests were taken.  One using NIR forage testing methods and another using Wet Chemistry.  July 11 and July 17 test were only done using wet chemistry, since it was clear this was the most accurate test for native prairie grass.  No forage testing was completed after July 17 since forage quality was declining and would not be quality cattle feed.  Forage samples were taken at noon, during sunny days to capture the best sugar content in the grasses.  One of the sample days we did have a smokey haze from the Canadian wildfires, and this did result in lower sugar levels in the grass.  

Prairie Soil Health: On June 15,2023 we took samples in a dry prairie hillside, mesic prairie base of the hill and a mesic non-native pasture that has been managed organically as pasture for 6 years.  The non-native pasture has been tested for the last two years.  All locations were farmed conventionally as row crops previously, but have been managed organically in perennial forages for the last 6 years.  We used Midwest Laboratories soil health test calculation which looks at multiple indicators of soil health.  This was a drought year, and that does seem to affect the test score, likely because the soil life is limited by the drier conditions.

Plant community

The prairie pasture plant community composition data is described by overall species richness (i.e. # of unique plant species encountered), by frequency, and by abundance. Plant composition data was collected from eight 0.5 m x 0.5 m quadrats evenly distributed along a 100 ft transect. Two transects, each with eight quadrats, were randomly placed in three different paddocks – including deferred and grazed paddocks – throughout the pasture to capture the existing variation in plant species distribution and any that might be caused by differences in grazing “intensity” from previous and future years. Plant species were noted as “present” if they were observed within each quadrat. While we hoped to collect additional data – such as % cover, height, vegetative regrowth – that may better describe how the plant community responds to grazing, we did not have the time to do so.

The plant community survey was conducted in late June before cows had grazed the paddocks. Frequency of plant presence for each paddock and the pasture as a whole was calculated by dividing the sum total of times a plant was observed in a quadrat by the number of quadrats for a given paddock (16 quadrats) or the whole pasture (48). Plant abundance was calculated by dividing the sum total of times a plant was observed in a quadrat by the total number of species observations collected.

Floral Blooms

The number of plants and number of species of floral blooms in the planted prairie pasture was collected in late June, mid-July, mid-August, and late September. Fifteen 6.5 ft x 1.5 ft quadrats were evenly spaced along a 100 ft transect, with data collected from two transects placed in three to six paddocks across the pasture – including both grazed and deferred paddocks. Species were recorded as present if they were in bloom and inside a quadrat at the time of the survey. Counting individual flowers on each plant, while ideal, was too time consuming to complete.

Bloom frequency and bloom abundance were calculated by paddock as well as pasture wide as described in the plant community survey section.

Bees

Bee surveys were completed across the pasture – representing both grazed and deferred paddocks – in mid-June, mid-August, and late September. Surveys were conducted following WIBee protocols for methodology and adapted using Xerces’ community science guidance for bee functional grouping. A 3 ft x 3 ft space containing a flowering plant or plants was observed for 5 minutes with all bees (native and honey) as well as flies, wasps, and beetles landing on a flower within the survey space noted as present and the number of times a unique insect visitor was observed to land on the flower. Bee functional groups included bumble bees, striped sweat bees, green sweat bees, medium dark bees, tiny dark bees, and hairy belly bees. Bee surveys included both native plants as well as introduced species that were flowering within the pasture.

Butterflies

Butterfly surveys were conducted using a pollard walk of the entire prairie pasture in June, July, and August. Surveys began about 11 - 11:30 am  and lasted 2 hrs. The pollard route followed the perimeter of each paddock through the middle – at a paddock’s base, mid-slope, and up-slope boundary. All butterflies observed to be within or crossing the transect route – buffered by 15 feet in front, behind, and on either side of the observer –  were recorded as present. These include butterflies that were flying through, resting, feeding, or mating and that could be identified visually in the field or briefly captured in a net and then released.

Research results and discussion:

Prairie Forage Quality Research:  The comparison between NIR and Wet Chemistry forage testing of native prairie grasses showed clearly that the current NIR is inadequate to show the quality of native prairie grass for cattle grazing.  RFV and RFQ are also poor tests to determine prairie grass quality.  The NIR test consistently showed lower levels of sugar, NDFD 30 and Total Digestible Nutrients that the wet chemistry tests.  NIR testing also showed much higher lignin levels in the grass that the wet chemistry test, which would suggest that the grass is not very digestible, when in reality the forage was very digestible with very good levels of energy.  Cattle performance and preference for this type of forage indicates the wet chemistry test is closer to reality.  Both tests show lower protein levels in the grass that would be ideal for cattle, levels of 12-14% crude protein, trending lower as that grass plant matures.  But cattle in these pastures did select forbs and legumes, which were not included in the forage test, but likely provide the protein levels they need.  Full prairie forage tests are provided here with a non-native pasture sample from late June on our farm included to show the similar forage quality results.  Ryan Heinen 6-5-23 Warm Season Pasture - Native wet chem180793 STD Ryan_Heinen_6-12-23_Prairie_NIR_Pasture_1459068_STD Ryan_Heinen_6-12-23_Warm_Season_Prairie_Pasture_Wet Chem Ryan_Heinen_6-20-23_Prairie_NIR_Warm_Season_Pasture_1460414_STD (1) Ryan_Heinen_6-20-23_Prairie_Pasture_-_Warm_Season_181193_STD Ryan_Heinen_6-27-23_Prairie_NIR_1461652_STD Ryan_Heinen_6-27-23_Prairie_Wet_1461651_STD (1) Ryan_Heinen_7-3-23_Prairie_Wet_1462605_STD (1) Ryan_Heinen_7-3-23_Prarie_NIR_1462606_STD Ryan_Heinen_7-11-23_Prairie_Wet_181616_STD Ryan_Heinen_7-17-23_Prairie_Wet_-_Warm_Season_Native_Pasture_181785_STD GHF SARE Prairie Grazing Forage Quality 2023Non-native pasture forage test June 2023   

Prairie Soil Health: Both locations showed very good soil health, with both having an overall soil health score over 100% of the possible soil health calculation.  For comparison we have also done this soil health calculation on our 6-year old non-native pastures with equally high soil health scores measuring near or above 100%.  Soil moisture does seem to impact the results of this test, which makes since, because the test is ultimately measuring soil life, which is higher when moisture is not limiting.  These results suggest to me that diverse perennial pastures that are organically managed with the appropriate amounts of grazing and rest are the key to soil health no matter if they are native prairie or non-native pasture. Prairie and non-native pasture soil health 2023

Plant community

Plant community information forthcoming

Floral Blooms

Floral bloom information forthcoming

Bees

34 bee surveys were conducted across three visits in June, August, and September. 24 surveys documented bee visitation on a native plant while 10 surveys documented bee visits to an introduced species – either alfalfa (Medicago sativa) or clover (Trifolium repens). 6 surveys were completed before grazing began and 16 surveys were completed after vegetation had been grazed. Across the 34 surveys, 199 bee observations and 81 non-bee flower visitors (flies, beetles, wasps) were recorded. Native bees were observed in a given survey 82.35% of the time (28 surveys) while honey bees were observed in half (50.00%) of the surveys (17 surveys). Excluding the non-bee visitors, native bees were more often observed and composed nearly two-thirds (63.32% or 126) of the recorded flower visitors. Honey bees were less frequently observed, with 73 total visits or 36.68%.

The “type” (i.e. functional group) of native bee and the frequency that it was observed varied tremendously. Striped sweat bees were the dominant native bee visitor recorded, accounting for 80 of the 126 native bee visits (63.49%), followed by 18 tiny dark bee observations (14.29%), 14 bumble bees (11.11%), 7 green sweat bees (5.56%), 6 hairy belly bees (4.76%), and 1 medium dark bee (0.79%). Regardless of functional identity, all native bees appeared to strongly prefer native plants, with 92.06% of their visits (116) being recorded on a native plant. More so, three (3) functional native bee groups were never recorded visiting either of the introduced plant species. When honey bees were observed, 58.90% of their visits (43) were recorded on a native plant and 41.10% (30 visits) on an introduced plant.

Butterflies

In total, 19 unique species of butterflies were observed across the growing season: 14 species observed in June, 9 in July, and 11 in August. As the season progressed, the # of observations increased with 54 total observations made in June, 143 in July, and 244 in August. The majority of observations were made in the upper prairie pasture – up slope and east facing. The six most frequent species observed were pearl crescent (22.2%), cabbage white (21.5%), orange sulfur (21.5%), clouded sulfur (18.8%), monarch (7.3%), and eastern tiger (2.7%).

 

Participation Summary
2 Farmers participating in research

Educational & Outreach Activities

1 Tours
1 Workshop field days

Participation Summary:

30 Farmers participated
5 Ag professionals participated
Education/outreach description:

GHF SARE Prairie Grazing Forage Quality 2023 GLBW-Warmseason-fact-sheet-LPaine-Sep2020-FINAL-1 (1) Gwenyn Hill Seed Mix June 28 Gwenyn Hill Farm Pasturewalk

This year we conducted one pasture walk attended by 23 farmers, 5 agency or non-profit staff and 20 other people that had an interest in prairie. The pasture walk was about grazing warm season prairie plantings.  This event was well attended by farmers, neighbors and natural resource professionals.  We discussed how we were using grazing to manage our prairie plants, maintain and improve native plant, pollinator and wildlife diversity, and how the warm season native grasses fit in with our beef and dairy operations on the farm.  We also discuss restoration techniques, fencing, and use of prescribed fire. 

We also hosted our fall farm festival and tour which was attended by over 300 of our customers, neighbors and others interested in the farm.  The festival included a talk about the native pollinators and butterfly's that were observed in the grazed prairie during this summers survey work.

In Februray 2024 we will also be presenting our project results at the Marbleseed Conference, and Xerces Society will be putting out a blog article on the project.  

Learning Outcomes

20 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
Lessons Learned:

Forage Quality of Native Prairie Grass: The research we did this year on forage quality of native prairie grasses, a comparison between wet chemistry forage test vs. NIR forage tests was very interesting.  The NIR forage tests showed a lower forage quality than the Wet Chemistry tests showed. Given the cattle's eagerness to graze the forage I believe the wet chemistry test is closer to the actual value of the forage.  RFV and RFQ are poor tests in either testing method to show the value of native grasses to cattle. Generally, the NIR test show higher Lignin, lower sugar, higher starch, lower NDFD 30 and TDN 1x than is actually found in the native grasses.  From early June through the middle of July the sugar and digestible fiber in the grass was of very good quality with good levels of energy in the grass fiber and sugars with low lignin levels.  During this time period native grass forage quality based on fiber digestibility, starch and sugar was comparable to our cool season non-native dairy cow pastures.  This year we grazed dry cows, beef and dairy heifers on the prairie.  However, given the quality of the forage I will plan to graze our milking cow herd on the prairie.  By doing this I will also be able to see animal performance by measuring the daily milk production while on this type of forage.    

This was also a drought year on our farm.  This slowed the growth of both our non-native pastures but also the native prairie pasture.  However, it still produced a good amount of forage for our cattle, especially during a time of year (mid Summer) when our cool season non-native pasture growth was slowing down.  We were able to graze 15 head on 8.5 acres of prairie for a total of 6 days with a mixed herd of beef cow/calf pairs, dairy heifers, and dry milk cows.  This was approximately 10 animal units. 

On our farm having more of this forage would be of benefit to our grazing system, and allow more rest for the non-native pasture during the summer slump.  I think it would specifically fit in nicely on our steeper and drier pasture soils which are less productive overall, but the warm season, deep rooted prairie plants could produce just as much, if not more than the non-native grasses in these types of slopes and soils. GHF SARE Prairie Grazing Forage Quality 2023

Soil Health: Two locations in our prairie pasture were tested this year for soil health.  One location was a drier hillside and another was a more productive mesic prairie at the bottom of the hill.  Both location showed very good soil health, with both having an overall soil health score over 100% of the possible soil health calculation.  For comparison we have also done this soil health calculation on our 6 year old non-native pastures with equally high soil health scores measuring near or above 100%.  Soil moisture does seem to impact the results of this test, which makes since, because the test is ultimately measuring soil life, which is higher when moisture is not limiting.  These results suggest to me that diverse perennial pastures that are organically managed with the appropriate amounts of grazing and rest are the key to soil health no matter if they are native prairie or non-native pasture.  Prairie and non-native pasture soil health 2023

Project Outcomes

5 Farmers changed or adopted a practice
3 New working collaborations
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.